Liquid containers designed for use by infants and children comprise a receptacle that is closed at its top by a cap which is equipped with a spout in fluid communication with the interior of the receptacle, so that the infant or child can suck the liquid contained in the cup. This type of liquid containers is particularly suitable for infants and young children that cannot drink directly from a glass.
Very young children are not completely able to control their movements, and these containers are often turned upside down or shaken or part of the liquid contained therein accidentally leaks from the aforementioned spout of the lid.
Therefore, the need is felt to equip such containers with closure devices specially designed to prevent any accidental leakage of liquid from the spout, while ensuring that the infant or child can drink correctly by sucking from the spout. Prior art closure devices comprise silicone valves, operable in the lid and at the spout, which are normally closed, to close the spout in a fluid-tight manner, and can be only opened to let the fluid flow out of the spout when the child sucks from the spout and creates a negative pressure in the container.
These closure devices and particularly the aforementioned valves are often composed of many distinct parts that have to be coupled together and associated with the lid, which involves non-negligible assembly costs, as well as the drawback of requiring particular care by the user when cleaning the closure device (and hence disassembling the valves).
Therefore, the technical purpose of the present invention is to provide a closure device for containers, that can obviate the above mentioned prior art drawbacks.
Particularly, the present invention has the object of providing a closure device for container that has low assembly costs.
A further object of the present invention is to provide a closure device for containers that can be easily an effectively cleaned by a user.